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Table 2 Summary of values from which the power of the study are estimated

From: Genetic test to stop smoking (GeTSS) trial protocol: randomised controlled trial of a genetic test (Respiragene) and Auckland formula to assess lung cancer risk

  Control group expected quit rate as %ge Respiragenegroup expected quit rate as %ge χ2calculated from four-some table P value based on χ2 Power calculations*
8 weeks Sample size 30/30* 70% 94% 5.9 <0.05 79.3%
Sample size 60/60* 11.7 <0.01 96.9%
6 months Sample size 30/30** 35% 52% 1.7 NS 36.5%
Sample size 60/60** 6.2 <0.05 87.1%
  1. *Telephone (alone) quit rate (see Table 1) assumed to be 20%.
  2. **Telephone (alone) quit rate (see Table 1) assumed to be 10-15%.